Time-Driven Activity-Based Costing (TDABC) is a before-the-fact simplification method that simplifies the first stage of assigning costs to activities of activity-based costing (ABC) system by: a. expanding the number of activity rates used so that the rates reflect the actual consumption of overhead costs. b. allocating weights and setting the result equal to the product's consumption ratio. c. recognizing that many of the so-called fixed overhead costs vary in proportion to changes other than production volume. d. eliminating the need for detailed interviewing and surveying to determine resource drivers